1. Chapter 5
Body, Brain, and Health

2. The Endocrine System the body’s “slow” chemical communication system
a set of glands that secrete hormones into the bloodstream

3. Hormonal Influences on Growth and Development

4. Neural Communication

5. The Brain and Nervous System
Neurons
Dendrite, cell body, and axon

7. Principles of Growth
Cephalocaudal principle
Growth occurs in a head-to-tail direction
Proximodistal principle
Growth and development of muscles from the center outward to the extremities
Orthogenetic principle
Development starts globally and undifferentiated
Moves toward increasing differentiation and hierarchical integration

8. The Infant
Synaptogenesis
Growth of synapses, during childhood
Synaptic pruning
Removal of unnecessary synapses
Developing brain has plasticity
Responsive to the individual’s experiences and can develop in a variety of ways

9. Figure 5-2

11. Plasticity
Responsiveness to experiences
Can be negative
Vulnerable to damage
Environmental deprivation
Can be positive
Aids in recovery from from injury
Can compensate for each other
Can benefit from stimulation
Allows for adaptability

12. Emotional Content of Language
Visual-spatial
Emotional Content of Language
Psychology 7e in Modules

13. Brain Lateralization
Figure 5.7 The brain consists of two hemispheres that specialize in different functions

14. Our Divided Brain large band of neural fibers
Corpus callosum
large band of neural fibers
connects the two brain hemispheres

15. Brain Development
Never truly complete
Changes occur across lifespan
Growth spurts in infancy, childhood and adolescence
Full adult weight by about age 16
Processing speed increases in adolescence
Myelination continues into adulthood

16. The Changing Brain
Brain development is never truly complete
Neurogenesis
Process of generating new neurons
Elderly adults may end up with 5–30% fewer neurons than early adulthood
Neuron loss greater in areas that control sensory and motor activities
Increased activity in the prefrontal cortex

17. Brain Development
The Aging Brain
Gradual and mild degeneration
Elderly adults
5-30% fewer neurons than younger adult
Greater loss in sensory-motor areas
Plasticity still possible
Main result of age is slower processing

18. Programmed theories of aging Maximum life span (species specific)
Hayflick Limit – cells from embryos divide a limited amount 50 ± 10; for adult cells even less
telomeres

19. Random error theories of aging
Free radicals – toxic by-products of the metabolism of O2 damage cells and their functioning (also damage DNA)
Interaction of the two – or more